• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1994.11a
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• pp.108-117
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• 1994

본 논문에서는 공개키방식 알고리즘과 대칭키방식 알고리즘을 혼합하여 사용하는 혼합방식 암호시스템 (CHyCK:Certificate-based Hybrid Cryptosystem of KAIST) 의 구현에 대해 설명한다. CHyCK는 전송하고자 하는 메세지를 대칭키 암호알고리즘을 이용해서 암호화하고 이 때에 사용되는 대칭키를 공개키방식으로 암호화하여 상대방에게 암호화된 메세지와 함께 보내게 된다. CHyCK는 공개키방식에서 사용되는 키쌍 중 공개키를 안전하게 가입자에게 분배해 주는 방법으로 인증서기반(certificate-based)방식 을 채택하였다. 또한 이를 위해서는 인증서를 발급해 줄 인증기관(certifying authority)이 필요하게 된다. 그리고 시스템을 구성하는 기본 암호알고리즘들은 기존의 것들 중 적합한 것으로 선택했다. 마지막으로 본 논문에서는 시스템의 안전성을 키분배와 메세지 전송 측면에서 분석했다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.97-106
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• 2003

The important factor in Public-Key Infrastructure is the authentication to correspondent. We receive the digital certificate for authentication between each other, and then we check the existence of validity on the certificate by Certification Revocation List(CRL). But, To use CRL is the scheme used in offline status. So, it is impossible to refer to the latest information and the CRL scheme which is used after downloading is variously unsuitable to getting bigger of the CRL size as time goes on. Therefore, we prefer OCSP(Online Certificate Status Protocol) used in online to CRL used in offline. Consequently, we propose the scheme which provides the request of fast verification in case of requesting the verification on the certificate by owning the same update information to Certificate Registry and distributed OCSP.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.171-180
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• 2008

This paper also suggests the Digital Evidence Transmission System for E-Discovery which is suited to domestic environments in order to solve these problems and promote safe and convenient transmission of the electronic evidences. The suggested Digital Evidence Transmission System for E-Discovery is the system that submit digital evidences to Court's Sever through the Internet using Public Key Infrastructure and Virtual Private Network, and solves the problems - such as privileged and privacy data, trade secret of company, etc.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.4
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• pp.591-599
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• 2023

Due to the recent attack by Castryck-Decru, the private key of SIDH can be recovered in polynomial time so several methods have been proposed to prevent the attack. Among them, M-SIDH proposed by Fouotsa et al, counteracts the attack by masking the torsion point information during the key exchange. In this paper, we implement M-SIDH and evaluate its performance. To the best of our knowledge, this is the first implementation of M-SIDH in C language. Toward that end, we propose a method to select parameters for M-SIDH instantiation and propose a 1024-bit prime for implementation. We implemented the square-root Velu formula over the extension field for further optimization. As a result, 1129 ms is required for a key exchange in the case of MSIDH-1024, providing the classic 64-bit security level.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.151-161
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• 2009

In Location-Based Services (LBSs), users requesting a location-based query send their exact location to a database server and thus the location information of the users can be misused by adversaries. Therefore, a privacy protection method is required for using LBS in a safe way. In this paper, we propose a new cloaking region generation algorithm using grids for privacy protection in LBSs. The proposed algorithm creates a m inimum cloaking region by finding L buildings and then performs K-anonymity to search K users. For this, we make use of not only a grid-based index structure, but also an efficient pruning techniques. Finally, we show from a performance analysis that our cloaking region generation algorithm outperforms the existing algorithm in term of the size of cloaking region.

• Convergence Security Journal
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• v.14 no.6_2
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• pp.35-44
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• 2014

Private Security Guard Certification Exam that initiated as the eligibility of private in 2006, has been requested more fulfilling management because that becomes to be recognized at the national certified qualification system in 2013. The findings of this study were as follows: First, it is necessary to expand more exemptions, currently some are mainly police officers. Secondly, it is needed to make to announce the final successful candidates through the opposition proceedings by publishing assumptions answer of the problem and by improving the procedure for determining the successful candidates, and so forth.

• 한국벤처창업학회:학술대회논문집
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• 2023.11a
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• pp.43-47
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• 2023

인간은 만물의 영장류이다. 그러나 피할 수 없이, 부모의 불완전성과 사회적·환경적 이유들로 인해 아이는 의존적 욕구와 본능적 욕구의 좌절을 겪을 수밖에 없다. 이 두려움으로부터 자신을 보호하고, 부분적으로라도 욕구의 충족을 얻을 방법을 습득한다. 이 방법이 방어기제이며, 이것이 개인의 성격 특성으로 나타난다. 특히 사회적·도덕적으로 용납되지 못하는 성적 충동, 공격적 욕구, 미움, 원한 등은 하나의 위험으로 인식되고 불안을 일으킨다. 1번 유형 개혁가, 이들은 높은 이상을 실현하기 위해서 끊임없이 노력하는 활동가이다. 이들의 교류방식은 자신의 견해가 옳다고 여기기 때문에 이런 신념이 강할수록 상대방을 가르치고, 고쳐주려고 한다. 2번 유형 조력가는 쉽게 다른 사람과 친해지는 장점이 있다. 3번 유형 성격 성취가는 사회 속에서 성공을 바란다. 4번 유형 성격 예술가, 깊은 직관력으로 창조적인 영감과 기쁨을 찾는다. 5번 유형 관찰가, 이들의 본질은 깨달음이다. 6번 유형 충성가, 이들의 본질은 두려움과 의심을 극복함으로써 드러난다. 7번 유형 열정가, 침체된 분위기를 고조시키는 재능을 가지고 있다. 8번 유형 도전가, 돌려서 이야기하는 사람을 좋아하지 않는다. 9번 유형 중재자. 다른 사람과 갈등이 있으면 다른 사람의 입장을 먼저 생각한다.

• Korean Journal of Culture and Social Issue
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• v.12 no.2
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• pp.45-76
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• 2006

This article compares the psychological and behavioral profiles of adolescents on probation and high school students. A total of 253 adolescents on probation and 257 high school students completed an open-ended questionnaire developed by the present researchers and structured questionnaire that assessed moral disengagement and self-efficacy developed by Bandura (1995), delinquent behavior and academic achievement. Adolescents on probation reported that they engaged in delinquent behavior due to the fault of others and they were angry for being forced to be on probation. They are not likely to take responsibility and morally disengage from their delinquent actions. When compared to high school students, adolescents on probation are likely to report low self-efficacy, low academic grade, and less likely to feel proud of themselves. They are more likely to meet their friends in Internet and video game rooms and less likely to focus on academic achievement. Results of ANCOVA indicate that adolescents on probation have higher scores on moral disengagement, social efficacy, but lower score on efficacy for self-regulated learning. They are more likely to run away from home and have lower academic grade. The results of the discriminant analysis indicate that running away from home, social efficacy and moral disengagement are predictive of adolescents on probation and academic achievement and efficacy for self-regulated learning are predictive of high school students.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.115-126
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• 2009

Recent development in wireless communication and mobile positioning technologies makes Location-Based Services (LBSs) popular. However, because, in the LBSs, users request a query to database servers by using their exact locations, the location information of the users can be misused by adversaries. Therefore, a mechanism for users' privacy protection is required for the safe use of LBSs by mobile users. For this, we, in this paper, propose a efficient cloaking region creation scheme using Hilbert curves in distributed grid environment, so as to protect users' privacy in LBSs. The proposed scheme generates a minimum cloaking region by analyzing the characteristic of a Hilbert curve and computing the Hilbert curve values of neighboring cells based on it, so that we may create a cloaking region to satisfy K-anonymity. In addition, to reduce network communication cost, we make use of a distributed hash table structure, called Chord. Finally, we show from our performance analysis that the proposed scheme outperforms the existing grid-based cloaking method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.971-984
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• 2004

In the coming age of information warfare, information security patterns need to be changed such as to the active approach using offensive security mechanisms rather than traditional passive approach just protecting the intrusions. In an active security environment, it is essential that, when detecting an intrusion, the immediate confrontation such as analysing the intrusion situation in realtime, protecting information from the attacks, and even tracing the intruder. This paper presents an active intrusion-confronting system using a fake session and a honeypot. Through the fake session, the attacks like Dos(Denial of Service) and port scan can be intercepted. By monitoring honeypot system, in which the intruders are migrated from the protected system and an intrusion rule manager is being activated, new intrusion rules are created and activated for confronting the next intrusions.